High molecular weight carboxylic acids



Patented Feb. 20, 1951 HIGH MOLECULAR WEIGHT CARBOX-YLIC ACIDS Howard D. Hartough, Pitman J. assignor. to

Socony-Vacuum Oil- Company, Incorporated, a

corporation ofNcwYork No Drawing, implication October 16, 1945,

Serial No. 622,681.

11 Claims. I,

The present invention relates to the preparation. of high molecular wei ht. fatty acids and, more particularly, to the condensation of alkyl. and acyl halides with unsaturated acids having at least one replaceable hydrogen in an alkyl chain.

It is an object of the present invention to.pro..-. vide a method for producing alkyl and/or acyl substituted" aliphatic carboxylic acids. It. is an other object of the present invention to provide a means of increasing the molecular weight of aliphatic carboxylic acids. It is a further object of the present invention toprovide'a method for producing fatty acids having a molecular weight of at least 300; Other objects and advantages; will become apparentfrom the following description.

In general, the present method oi increasing the molecular weight of unsaturated aliphatic carboxylic acids having a replaceable hydrogen atom in an alkyl group comprises condensing an alkyl halide or an acyl halide withan aliphatic carboxylic acid of the. Class previously mentioned at. an elevated temperature below that oi reflux in the presence Of a condensation agent of the Friedel Crafts, type. After the evolution of hyr eion halid ha ce s indica e that. he. ret on is subs ant ally comple e the. rea tion. ulie s t a d to remov the ondensation. agent and unreacted components of the original reaction mixture and the acid of increased molecular weight recovered; in any suitable manner.

While an lkrl oracid halid ay housed, it is preferred primarily for reasons ofeconomy, o use. he hloride The, unsa urated; a ipha ic cids. such as cr t nio maleic; o elo and he ike are used.

The alkyl halides may be of relatively low molecular weight, such as methyl halide, or of relae y hi h mo cu ar eight, such; aslaurrlr otade yl" h ide:

hus, oleic a id; may he condens d wi m t l:

halide or cr t ni a ld. conde sed w th otadeerl spendin acid anhydridesmay replace the acids.

A rli hali es. such a aoet l" halide or stoaroyl'halide manalso be employed.

in both the reaction to produce an alkyl substituted unsaturated. aliphatic acid and the 'ketoaliphatic acid. The. unsubstituted acids in ues-l tion may be said to have the. empirical formula.

qual. to 1 or, hile he substi u d solos have e e p r c l lormole R RhlCOQH Qle. w ere.

, a is, allgenyl grou s. el ted r m e srl nd. orl mdioelshavin or o eleoees a= q o mo rel b= l r 2 and n= o more.

Although any oft e cond ns n a en s of. the s time may be userllt. is. rz efelre l,

chlo ide. (f sed or anhyd us). be: cause the side eact ons etelfs uoed n he sepaned l-Qr it o employ zin etl nofthe deslr clproduet rom unreeeted meerlslsl resinous materials and the i e is 54231; ated,

the reaction s carr ed out, at. tensperatures. sh e lQqt eer s e ti rade. under pressure it some reflu usu ly oowhen reac ion s. arrie t at 3 2 .39.57-

pherie press1.111s.= It has. bee oun that. te

peratures of. the order o 0. de e s t 2. 0, do. erees oentier de Pro de sa sfact y res1 s.-. Temperatures oi 2. .c er. sto eer esc al a ere eare el rredl lt to. e. under tood ha he rea tion merrequ lieun to 9 r 10 hour a er he evolution oi hydrogen hal e has become. oerptlble to rea p act cal com e on: Durin he heati the. react on mi ure a t the.

olntlono hydro en hal de has become ercen l ble hete npe e urem y be w r 15 o 3.0 eoss e ntlere e below h t a w ich h 3694. 7

tion as carried horlo to he lution of the hydro en alide.

the. fur h r nli htenment. o ho sk lled L n the art. the loll wlne illu tra iv exam les are, eoylded. However... it s. to be unde stoodthet.

hese examples ereno limitine.

' Exampl I One hundred parts by weight of 20 per cent chlorowax (made from paraffin wax having an A! T. M. melting point oi and 156. parts.

by weight of a mixtureof fiatty acids-and 38 parts, by weight of anhydrous zinc chloride were mixed and slowly heated to l2!) degrees. centigrade Evolutionof hydrogen chloride became vigorous at. 120: degreesicentigrade and:continued through the temperature; range 120-135- degrees centie grade. Theheating of the reaction mixture was continued for about. 3 hours, after which time purposes had ceased, the reaction mixture was.

water-washed three times to remove the zinc chloride. When it is desired to improve the color of the finished product, a small amount of zinc dust is added to the reaction mixture before Water-washing. The reaction mixture is cooled and after diluting with a suitable solvent, say benzol or the like, the diluted reaction mixture containing the zinc dust is treated with dilute mineral acid. Thereafter, the reaction mixture is treated to remove zinc chloride and excess mineral acid, hydrochloric acid, for example, as by water-washing. The solvent is then removed in any convenient manner as by distillation to leave the desired product as a still residue. When desirable the still residue can be further purified in any suitable manner. a

The mixture of fatty acids which has been reacted as described hereinbefore has the following composition:

The chlorinated paraffin wax, or chlorowax as it issometimes called, is pre ared from a parafiin wax having an A. S. T. M. melting point of about 120 F. to about 130- F. This wax is predominantly a mixtureof aliphatic hydrocarbons having more than 20 carbon atoms in the moleculeand averaging about 24 carbon atoms in the molecule. 1 The mixture as an average molecular wei ht in the neighborhood of 340.

The wax is melted and heated to about 200 F.: chlorine can be bubbled throu h until the desired amount, about 20 per cent is absorbed. Hi her temperatures may be used to accelerate the reaction but ifatoo hi h are likely to darken the product. The product contains monoas well as poly-chlorinated parafi ns together with a small amount of unchlorinated material. skilled in the art will understand that paraffin wax with a much higher chlorine content, say about 45 er cent, may also be used.

The still residue was found to be soluble in hot per cent potassium carbonate solution. Upon analvsis the still residue was found to have a neutralization number (N. N.. -mg. KOH/ of 99.5, a sa onification number (S. N.) of120.9,

Those 4 Example II One hundred parts by weight of per cent chlorowax, 159 parts by weight of oleicacid and 10 parts by weight of anhydrous zinc chloride were mixed and treated as in Example I. The product had a neutralization number of 73.8, a saponification number of 86, an iodine number of 52, a residual chlorine content of 2.05 per cent and a molecularweight of 885.

The calcium salt of this acid was prepared by treating the acid with equimolar quantities of aqueous potash. The potassium salt thus obtained was converted to the calcium salt thereof by the addition of aqueous calcium chloride. The calcium salt was a powdery white solid. Analysis: 1

' Per cent Calcium observed 5.1 Calculated for molecularweight 898 4.6 Calculated for Ca(C17Hs3COO) 2 8.1

an iodine number (mg. I/g'.) of 38 and a molecular weight of 181.5.

and an avera e-molecular wei ht o 280. Accord- The fattv acids used as starting material have a calc lated iodine number of 184-190, a neutralization number of 202,

ingly, it would appear that the still roduct is a mixture of acids produced bv alkylating about 4 molecules of fatty acid with 2 molecules of wax. Thus, the wax po tion of the molecule has a molecular wei ht of 672, the average molecular weight of the fatty acids is about 280; 1815 minus 672-equals 1143; 1143/280=4.

Observed molecular weight 1815 Calculated molecular weight 1794 Observed saponification number 120.9 Calculated for 01161-1222(CQOH)4 of stearoyl chloride and 10 parts of anhydrous Consequently, the ob- The calcium salt appeared to be that of an acid having the empirical formula C24H4s(C1'lH32COOI-I) 2 or CssH112(COOH) 2 having a calculated molecular weight of 898 as compared with an observed molecular weight of 885:10 per cent. Thecalv culated iodine number for such a substituted oleic "acid would be 57; the observed value was 52. r

Example III One hundred and fifty parts by weight of 20 per cent chlorowax, 83 parts by. weight maleic 'anhydride and 10 parts by weight anhydrous zinc chloride were mixed and heated slowly. At

degrees to degrees centrigrade the evolution of perature of the reaction mixture was maintained at degrees to degrees centigrade for two hours followed by a period of one hour ata temperature of degrees to degrees centigrade.

The reaction mixture was worked up as described hereinbefore. The product had a neutralization number of 58, a saponification number of 151, a-

residual chlorine content of 0.01 percent and a molecular weight of 1625:10 per cent. A substituted maleic acid of the following formula c-ooon Cua m v C-C-OOH 2 i would have a molecular weight of 1572 and a saponification number of 142. The. calculated saponification number for this acid is 142 which is to be compared with an observed saponification number of 151.

. Example IV Forty parts by weight of maleic acid, 115 parts zinc chloride were mixed and treated as'in Example I. The solid waxy material gave the following analyses: neutralization number=90,

saponification number=148, and molecular weight=758. It is to be noted that the foregoing is illustrative of the method of producing ketoacids. Example V Two hundred and four parts (1 mole) of lauryl chloride and 280 parts (1 mole) of oleic acid were thoroughly mixed. To the mixture was added 40 parts by weight of .fusedzinc chloride.

The reaction mixture was heated to degrees centi-c grade for 90: minutes before. the. evolution of bi drogen. chloride was noted. (At this time; the: anon sludge ape'ared to go into solution.) Some: reflux was observed and the temperature was lowered to. about 16.0 degrees centigrade and held at this temperature for about 9 hoursuntil the evolution of hydrogen chloride had become negligible. The. reactionmixture was: treated further as. in previous examples with the unretacted lauryl chloride and'ole'ic acid being topped under vacuum. The yield 01 alkylated acid was 3 15* parts: by weight. The product had a neutralization number of 74, a saponifi'cationnumber of 107; an iodine number of? 55 and a molecular weight of 587. 1

The calcium salt of this alkylated acid was preparediby' adding grams oi the acid to 074 gram of potassium hydroxide dissolved in 50 milliliters of absolute alcohol. Fifty milliliters of absolute alcohol were added and solution boiled for minutes to obtain the potassium salt. A solution of anhydrous calcium chloride in absolute alcohol was made by dissolving 075 gram of anhydrous calcium chloride in milliliters of absolute alcohol. The calcium salt of the alkylated acid was made by adding the solution of calcium chloride to the solution of the potassalt of the alkyl'ated acid. A gelatinous precipitate was formed. immediately. The alco holic solution was decanted from the precipitate and the precipitate digested 10 minutes with 50 milliliters of boiling. alcohol. The. suspension was allowed to settle and the alcohol decanted. Upon evaporation. 3.5 grams of material were recovered. This material was acidic indicating uni-e acted acid. The alcohol-washed precipitate was dissolved in petroleum ether, in which calcium oleate and calcium stearate are insoluble, and 0.80 gram of potassium chloride was removed by filtration. On evaporation of the petroleum ether 7.0 grams of the calcium salt of the alkylated oleic acid were recovered. 1.0020 grams of this calcium salt were ashed to give 0.0475 gram of calcium oxide (CaO) equivalent to 3.38 per cent calcium. A calcium salt containing 3.38 per cent calcium has a molecular weight of 1183. To produce a calcium salt having a molecular weight of 1183 the monobasic acid from which the salt is produced has a molecular weight of 572.

In a similar manner a cobalt salt of the alkylated oleic acid was prepared. 1.0773 grams of the cobalt salt when ashed gave 0.0750 gram of cobalto-cobaltic oxide (C0304) equivalent to 5.11 per cent cobalt. The molecular weight of a salt containing 5.11 per cent cobalt is 1195. To produce a salt of this molecular weight, an acid having a molecular weight of 569 is required. To produce an acid of molecular weight of 569-587 a mixture of monoand dilauryl oleic acid must be present since a monolauryl oleic acid would .have a molecular weight of 450 and a dilauryl oleic acid would have a molecular weight of 619. Therefore, it would appear that the product obtained was a mixture of monolauryl and dilauryl oleic acids containing 28 per cent of the mono-derivative and '72 per cent of the disubstituted oleic acid.

The topped reaction product had a saponiiication number of 107. A mixture containing 28 per cent mono-, and 72 per cent dilauryl oleic acid will have a saponification number of 100. The calculated iodine number for such a mixture is 48.5, which checks the observed value of 55.

It will be observed that the reaction products obtained bycondensingan alkyl or acyl halide I claim 1.:The method of producing unsaturated aliphatic carboxylic acids having a molecular weightof about 1800 which comprises reacting aboutparts by weight of 20 per cent chlorowax andiabout 155' parts by weight of a mixture of fatty acids containing about 37 to about 4-2 per l mice of" about 38 parts by weight of anhydrous zinc chloride at about to about C. to obtain a reaction mixture, water washing the reaction mixture to remove zinc chloride and de hydrating said washed reaction product.

2. The method of producing substituted oleic acid which comprises mixing 100' parts by weight of 20 per cent chlorowax, 159 parts by weight of oleic acid and parts by weight of anhydrous zinc chloride to form a reaction mixture, heating said reaction mixture to a temperature of about 120 to about 135 0., water washing said reaction mixture to remove zinc chloride and dehydrating said water washed reaction mixture.

3. The method of producing substituted unsaturated aliphatic carboxylic acids having a molecular weight of about 885 to about 900 which comprises mixing about 100 parts by weight of 20 per cent chlorowax prepared by chlorinating parafiin wax having a melting point of about 120 F., about 160 parts by weight of unsaturated aliphatic carboxylic acid and about 10 parts to about 40 parts by weight of anhydrous zinc chloride to form a reaction mixture, heating said reaction mixture at about 120 C. to about 135 C. to obtain a reaction product, water washing said reaction product to remove zinc chloride, and dehydrating said reaction product.

4. The method as set forth and described in claim 1 wherein the reaction mixture is cooled, diluted with a solvent to form a solution of the reaction product, zinc dust and mineral acid are added to the solution of reaction product to improve the color of the product, the solution is water washed and the washed solution distilled to remove solvent and leave a product of improved color as a still residue.

5. Alkyl substituted maleic acid having a molecular weight in excess of 1500 and a saponification number of about 151.

6. A mixture of monoand dilauryl oleic acid having a molecular weight of about 587, a saponification number of about 107, and an iodine number of about 55.

7. The method of producing an unsaturated aliphatic carboxylic acid having increased molecular weight from a lower molecular weight unsaturated aliphatic carboxylic acid, which com-- prises: reacting a halide selected from the group consisting of an alkyl halide and an acyl halide, all carbon atoms of said alkyl and acyl halides being of aliphatic character, with said lower molecular weight acid in the presence of Zinc chloride at an elevated temperature above ambient temperature and not greater than that of reflux; and separating said acid having increased molecular weight from the reaction mixture thus formed.

8. The method of producing an unsaturated aliphatic keto acid which comprises: reacting an acyl halide, all carbon atoms of which are of aliphatic character, with an unsaturated aliphatic carboxylic acid in the presence. of zinc chloride at a temperature between about 100 C. and about 200 6.; water washing the reaction mixture thus formed to remove zinc chloride therefrom; and dehydrating said water-washed reaction mixture, thereby obtaining said keto acid.

9. The method of producing an unsaturated aliphatic carboxylic acid having increased molecular weight from a lower molecular weight unsaturated aliphatic carboxylic acid, which comprises: reacting 'an alkyl halide, all carbon atoms of which are of aliphatic character, with said lower molecular weight acid in the presence of zinc chloride at a temperature between about 100 C. and about 200 (3.; water washing the reaction mixture thus formed to remove zinc chloride therefrom; and dehydratingsaid waterwashed reaction mixture, thereby obtainingsaid unsaturated aliphatic carboxylic acid having increased molecular weight.

10. The method of producingan unsaturated aliphatic polycarboxylic acid from an unsaturated bythecondensation of one of the group alkyl and acyl halides, all carbon atoms of which are of aliphatic character, with an unsaturated aliphatic carboxylic acid.

HOWARD D. HARTOUGH,

REFERENCES CITED I he following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,927,295 Powers Sept. 19, 1933 2,060,195 Goldschmidt et a1. Nov. 10, 1936 2,144,324 Bowles et all Jan. 17, 1939 2,210,305 Rheineck "Aug. 6,19401 2,293,649 HOWk A g. 18, 1942' OTHER REFERENCES .Qowan et al., Oil and Soap, August 1943, pp.

1276 (1937). Galloway. Chem. Rev. 17. 375 (1935).

acid, which compriseszjv Bradley et al., Ind. and Eng. Chem. 29, 1270-- Certificate of Correction Patent No. 2,542,772 February 20 1951 HOWARD D. HARTOUGH It is hereby certified that error appears in the printed specification of the above numbered patent requiring correctlon as follows:

Column 6, line 12, for the Word mole read more;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 31st day of July, A. D. 1951.

ERNEST F. -KLINGE,

Assistant Uommz'asz'oner of Patents. 

1. THE METHOD OF PRODUCING UNSATURATED ALIPHATIC CARBOXYLIC ACIDS HAVING A MOLECULAR WEIGHT OF ABOUT 1800 WHICH COMPRISES REACTING ABOUT 100 PARTS BY WEIGHT OF 20 PER CENT CHLOROWAX AND ABOUT 156 PARTS BY WEIGHT OF A MIXTURE OF FATTY ACIDS CONTAINING ABOUT 37 TO ABOUT 42 PER CENT BY WEIGHT LINOLENIC ACID, ABOUT 35 TO ABOUT 47 PER CENT ABOUT 38 PARTS BY WEIGHT OF ANHYDROUS 12 PER CENT BY WEIGHT OLEIC ACID, 8 TO ABOUT 11 PER CENT PALMITIC ACID AND STEARIC ACID IN THE PRESENCE OF ABOUT 38 PARTS BY WEIGHT OF ANHYDROUS ZINC CHLORIDE AT ABOUT 120 TO ABOUT 135* C. TO OBTAIN A REACTION MIXTURE, WATER WASHING THE REACTION MIXTURE TO REMOVE ZINC CHLORIDE AND DEHYDRATING SAID WASHED REACTION PRODUCT. 